2-butylaminoethanol

Endpoint summary

Description of key information

Irritation:
- skin: irritating (rabbit: BASF 2007)
- eye: severe damage (rabbit: BASF 2007)

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2500 (Acute Dermal Irritation)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Japan MAFF Testing Guideline of 12 Nousan No. 8147, adopted November 24, 2000

Deviations:

no

Remarks:

(as this is in line with OECD 404)

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Centre Lago S. A., 01540 Vonnas, France
- Age at study initiation: Ca. 7 months
- Weight at study initiation: 3.77 kg – 4.29 kg
- Housing: single housing in stainless steel wire mesh cages with grating, floor area: 3000 cm²
- Diet (about 130 g/animal per day): Kliba-Labordiaet (Kaninchen & Meerschweinchenhaltung “GLP”), Provimi Kliba SA, Kaiseraugst, Basel, Switzerland
- Water (ad libitum): tap water
- Acclimation period: at least 5 days
- Reasons for the selection of the test species: This animal species is the worldwide accepted test system for skin irritation / corrosion studies.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24
- Humidity (%): 30-70
- Photoperiod (hrs dark / hrs light): 12/12

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 ml of the undiluted liquid substance.

Duration of treatment / exposure:

4 hours

Observation period:

14 days

Number of animals:

3

Details on study design:

TEST SITE
- Area of exposure: flank
- Type of wrap if used: test patch (2.5 cm x 2.5 cm)

REMOVAL OF TEST SUBSTANCE
The test substance was removed at the end of the exposure period with Lutrol and Lutrol/water (1 : 1).

SCORING SYSTEM:
Erythema and eschar formation
Grading:
0 No erythema
1 Very slight erythema (barely perceptible)
2 Well defined erythema
3 Moderate to severe erythema
4 Severe erythema (beet redness) to eschar formation preventing grading of erythema

Edema formation
Grading:
0 No edema
1 Very slight edema (barely perceptible)
2 Slight edema (edges of area well defined by definite raising)
3 Moderate edema (raised approx. 1 mm)
4 Severe edema (raised more than 1 mm and extending beyond area of exposure)

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1.7

Max. score:

4

Reversibility:

fully reversible within: 72 h

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

2.3

Max. score:

4

Reversibility:

fully reversible within: 14 days

Remarks on result:

other: scaling was observed was observed on day 7 up to day 14 post application

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

3

Max. score:

4

Reversibility:

not fully reversible within: 14 days

Remarks on result:

other: severe scaling was observed on day 7 up to day 14 post application

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

1

Reversibility:

fully reversible within: 48 h

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0.33

Max. score:

1

Reversibility:

not fully reversible within: 48 h

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0.33

Max. score:

2

Reversibility:

fully reversible within: 48 h

Table 1: Irritant response, data for each individual animal at each observation time as well as calculation of the means.

		Exposure period: 4 h
Readings	Animal	Erythema	Edema	Additional findings
0 h	01	2	0
	02	2	0
	03	2	2
1 h	01	2	1	15,16
	02	2	1	15,16
	03	2	2	15,16
24 h	01	3	0	15
	02	3	1	15,16
	03	3	1	15,16
48 h	01	2	0	15
	02	2	0	15
	03	3	0	15
72 h	01	0	0	SD
	02	2	0	15
	03	3	0	15
7 d	02	1	0	S, 15, 17
	03	2	0	SS, 15, 18
14 d	02	0	0	S
	03	2	0	SS
Mean 24-72 h	01	1.7	0.0
	02	2.3	0.3
	03	3.0	0.3
Mean		2.3	0.2

15 = erythema extending beyond the area of exposure

16 = edema extending beyond the area of exposure

17 = scaling extending beyond the area of exposure

18 = severe scaling extending beyond the area of exposure

S = scaling

SD = study discontinued because the animal was free of findings

SS = severe scaling

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

BEA was irritating to skin.

Executive summary:

In a dermal irritation study (BASF, 2007; Report No. 18H0033/072033) according to OECD 404 and GLP the shaved skin of three New Zealand White rabbits was dermally exposed to 0.5 mL of the unchanged test substance for 4 hours under semiocclusive conditions. Animals then were observed for 14 days. Irritation was scored according to the method of Draize. Moderate or marked erythema (grade 2 or 3) was observed in all animals up to 48 hours and in two animals up to 72 hours after removal of the patch. One out of these two animals showed slight erythema (grade 1) on day 7 and the other animal exhibited moderate erythema (grade 2) up to study termination on day 14. Moderate oedema (grade 2) was noted in one animal up to 1 hour after removal of the patch and decreased to slight (grade 1) up to the 24-hour reading. Slight edema was noted in two animals after 1 hour and persisted in one out of them up to 24 hours. Both, erythema and oedema partly extended beyond the area of exposure. In addition scaling and severe scaling, both partly extended beyond the area of exposure, were observed in two animals on day 7 and 14. The results show, that the cutaneous reactions were reversible in one animal within 48 hours after removal of the patch. In another animal the cutaneous reactions with the exception of scaling were reversible within 14 days. The cutaneous reactions were not reversible in the third animal, which exhibited moderate erythema and severe scaling on day 14 (study termination). Mean scores over 24, 48 and 72 hours for each animal were 1.7, 2.3 and 3.0 for erythema and 0.0, 0.3 and 0.3 for oedema.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable, well-documented report which meets basic scientific principles.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

yes

Remarks:

(only 50 µL of the test substance were used and the observation period was 8 days)

GLP compliance:

no

Species:

rabbit

Strain:

Vienna White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 3.19 and 3.17 kg
- Diet: Sniff (no further details were given)
No further data.

Vehicle:

unchanged (no vehicle)

Controls:

other: The adjacent eye served as saline control.

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 50 µL

Duration of treatment / exposure:

single application

Observation period (in vivo):

8 days

Number of animals or in vitro replicates:

2

Details on study design:

SCORING SYSTEM: The original BASF grading was converted into the numerical grading according the OECD Draize system.

Irritation parameter:

cornea opacity score

Basis:

animal #1

Time point:

24/48 h

Score:

2

Max. score:

2

Reversibility:

not fully reversible within: 8 days

Irritation parameter:

cornea opacity score

Basis:

animal #2

Time point:

24/48 h

Score:

3

Max. score:

3

Reversibility:

not fully reversible within: 8 days

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

24/48 h

Score:

2

Max. score:

2

Reversibility:

not fully reversible within: 8 days

Irritation parameter:

conjunctivae score

Basis:

animal #2

Time point:

24/48 h

Score:

2

Max. score:

2

Reversibility:

not fully reversible within: 8 days

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

24/48 h

Score:

1.5

Max. score:

2

Reversibility:

not fully reversible within: 8 days

Irritation parameter:

chemosis score

Basis:

animal #2

Time point:

24/48 h

Score:

2

Max. score:

2

Reversibility:

not fully reversible within: 8 days

Irritation parameter:

iris score

Basis:

animal #1

Time point:

24/48 h

Score:

1

Max. score:

2

Reversibility:

not fully reversible within: 8 days

Irritation parameter:

iris score

Basis:

animal #2

Time point:

24/48 h

Score:

0

Max. score:

0

Reversibility:

other: not affected

Irritation parameter:

cornea opacity score

Basis:

animal #1

Time point:

24/48/72 h

Remarks on result:

not measured/tested

Irritation parameter:

cornea opacity score

Basis:

animal #2

Time point:

24/48/72 h

Remarks on result:

not measured/tested

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

24/48/72 h

Remarks on result:

not measured/tested

Irritation parameter:

conjunctivae score

Basis:

animal #2

Time point:

24/48/72 h

Remarks on result:

not measured/tested

Irritation parameter:

iris score

Basis:

animal #1

Time point:

24/48/72 h

Remarks on result:

not measured/tested

Irritation parameter:

iris score

Basis:

animal #2

Time point:

24/48/72 h

Remarks on result:

not measured/tested

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

24/48/72 h

Remarks on result:

not measured/tested

Irritation parameter:

chemosis score

Basis:

animal #2

Time point:

24/48/72 h

Remarks on result:

not measured/tested

Findings: animal 1 / animal 2

Time	corneal opacity	erythema	chemosis	iritis
1 h	2/3	0/2	2/1	0/0
24 h	2/3	2/2	2/2	0/0
48 h	2/3	2/2	1/2	2/0
72 h	-/-	-/-	-/-	-/-
8 d	3/3	2/2	2/2	2/0
mean	2/3	2/2	1.5/2	1/0

Mean values over 24 and 48 h. Effects were not evaluated after 72 h

The substance led to bloody secretion 1 h after application in both animals. Detachment of the cornea was observed in one animal 48 h after application. At the end of the observation period after 8 days necrosis of the eyelids, loss of hair around the eye, corrosion and purulence was observed.

Interpretation of results:

Category 1 (irreversible effects on the eye) based on GHS criteria

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

Butylethanolamine produced serious damage to rabbits' eyes.

Executive summary:

In a primary eye irritation study (BASF 1977) 0.05 mL of the unchanged test substance was instilled into the conjunctival sac of two Vienna White rabbits (without washing). Animals then were observed for 8 days. The original grading was converted into the numerical grading according to Draize. The test substance led to bloody secretion 1 h after application in both animals. Detachment of the cornea was observed in one animal 48 h after application. The mean (24 – 48 h) cornea, conjunctivae, chemosis and iris score was 2, 2, 1.5, 1 for animal 1 and 3, 2, 2, 0 for animal 2, respectively. All effects were not reversible within 8 days. Additionally, necrosis of the eyelids, loss of hair around the eye, corrosion and purulence was observed at the end of the observation period after 8 days.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irreversible damage)

Additional information

Skin irritation:

In a dermal irritation study (BASF, 2007; Report No. 18H0033/072033) according to OECD 404 and GLP the shaved skin of three New Zealand White rabbits was dermally exposed to 0.5 mL of the unchanged test substance for 4 hours under semiocclusive conditions. Animals then were observed for 14 days. Irritation was scored according to the method of Draize. Moderate or marked erythema (grade 2 or 3) was observed in all animals up to 48 hours and in two animals up to 72 hours after removal of the patch. One out of these two animals showed slight erythema (grade 1) on day 7 and the other animal exhibited moderate erythema (grade 2) up to study termination on day 14. Moderate oedema (grade 2) was noted in one animal up to 1 hour after removal of the patch and decreased to slight (grade 1) up to the 24-hour reading. Slight oedema was noted in two animals after 1 hour and persisted in one out of them up to 24 hours. Both, erythema and oedema partly extended beyond the area of exposure. In addition scaling and severe scaling, both partly extended beyond the area of exposure, were observed in two animals on day 7 and 14. The results show, that the cutaneous reactions were reversible in one animal within 48 hours after removal of the patch. In another animal the cutaneous reactions with the exception of scaling were reversible within 14 days. The cutaneous reactions were not reversible in the third animal, which exhibited moderate erythema and severe scaling on day 14 (study termination). Mean scores over 24, 48 and 72 hours for each animal were 1.7, 2.3 and 3.0 for erythema and 0.0, 0.3 and 0.3 for oedema.

In a second dermal irritation study (BASF, 1977; Report No. XXVI/45), New Zealand White rabbits (2 animals for each exposure period) were dermally exposed to the unchanged test substance for 1, 5, 15 min or 20 hours under occlusive conditions. Animals then were observed for 8 days. The original grading was converted into the numerical grading according to Draize. Exposure times of 1, 5 and 15 min caused reddening of the rabbit skin and oedema (only in 1 animal) beyond the area of exposure. One week later necrosis was seen (1 min and 5 min exposures: only in one animal, 15 min exposure: in both animals). An application for 20 h resulted in soft, grey necrosis after 24 h and parchment, severe necrosis after 48 and 72 h. Additional, the area around necrosis was reddened and light oedema was observed. Necrosis changed to full thickness necrosis in both animals and stayed until the end of the observation period.

The test conditions employed in this study are considered to be inadequate for the purpose of classificatin and labelling (intensified exposure due to occlusive conditions; length of observation period is to short to allow the correct evaluation of the reversilbility of effects) and therefore the resutls of this study have to be judged carefully.

Butylethanolamine was tested in an old skin irritation study in rabbits (Latven, 1977). The test was performed as prescribed in 49 CFR 173.240 (six albino rabbits, four hours skin-contact time, 48 hours observation). When exposures were terminated at four hours, the skin at all treated sites was reddish gray in colour. Oedema (Score 3) was present at 24 hours and 48 hours; at these times the sites were light gray in colour and pliable. No signs of skin corrosivity were discernible at any time.

Additionally, an in vitro test was performed. In the EpiDerm test conducted similar to OECD 431 (BASF, 2007; Report No. 61H033/072002) corrosive materials are identified by their ability to produce a decrease in cell viability. Viability of the test-substance treated tissues determined after an exposure period of 3 minutes was 56 % (1st experiment) and 60 % (2nd experiment). Viability of the test-substance treated tissues determined after an exposure period of 1 hour was 18 % (1st experiment) and 16 % (2nd experiment). Based on the observed results and applying the evaluation criteria, it was concluded, that the test substance shows not a corrosive potential in the EpiDerm skin corrosivity test under the test conditions chosen.

There are two disregarded studies, where butylethanolamine was tested in a Corrositex Continuos Time Monitor Assay (Microbiological Associates, 1993, 1995). The purpose of these studies was to evaluate the corrosivity potential of Butylethanolamine. The goal of this Assay is a measurement of a penetration of the test substance through a calibrated biobarrier into a chemical detection system (CDS). The experimental design of this study consists of a pH determination, if possible, a qualification screen with the Chemical Detection System (CDS), a categorisation screen, and a definitive Corrositex assay in the CDS. The Corrositex assay is evaluated on the basis of the colour change of the Chemical Detection System. The time that a colour change is observed is recorded manually and the break through time of a number of replicates is used to determine whether or not the test article is corrosive. The Packing Group was determined by the mean time interval the sample required to break through the biobarrier matrix. If corrosive, this information is also used to classify and assign a DOT packing group to the test article. In the first study, the test article was tested in one definitive assay (six replicates) to determine the Packing Group and the mean break through time (Microbiological Associates, 1993). In the second study, four replicates were used (Microbiological Associates, 1995). In both studies, the positive control, NaOH (>97 % purity), had break through times of 9:31, 9:48 and 12:50 (min/sec) which fell within two standard deviations of the historical mean (acceptance range: 9:31 to 14:06 min:sec and 9:12 to 13:54 min:sec), thereby meeting the acceptance criteria. Butylethanolamine had break through the time of 44 min and 40:40 (min:sec) in the first and in the second study, respectively. It corresponds to Packing Group II and is corrosive according to the criteria of these in vitro studies.

Conclusion on skin irritation/corrosion potential:

Butylethanolamine was irritating if applied to rabbits' skin in a fully reliable in vivo study performed according to OECD TG 404 and in accordance with the GLP.

In a non-GLP study, which was conducted equivalent to OECD TG 404 and under occlusive conditions, corrosive effects were observed. The result of irritating effects was also obtained by the in vitro EpiDerm skin corrosivity test in which three dimensional human epidermis model was used. However, the substance was corrosive according to the criteria for corrosivity of Corrositex Continuous Time Monitor Assay.

In conclusion, the result of the GLP vivo study, which is completely reliable according to the OECD TG, outweigh the result of the non-GLP in vivo study carried out under difficult exposure conditions (occlusive exposure).

The available in vitro Corrositex Continuous Time Monitor Assays (both from 1995) are not taken into account. This is due to the following: this approach has received approval as a replacement for in vivo skin corrosivity test. As such, as there is a reliable and even newer in vivo study available (BASF, 2007), these results are clearly outweighed and disregarded.

The further available in vitro study: the human keratinocyte study (EpiDerm skin corrosiveness test) has been scientifically validated and granted regulatory approval for the identification and classification of the corrosive potential of chemical substances. This test has been performed just month before the new and reliable in vivo study. In conclusion, its results are regarded to be appropriate and adequate to support the key in vivo study.

Eye irritation:

In a primary eye irritation study (BASF 1977; Report No. XXVI/45) 0.05 mL of the unchanged test substance was instilled into the conjunctival sac of two Vienna White rabbits (without washing). Animals then were observed for 8 days. The original grading was converted into the numerical grading according to Draize. The test substance led to bloody secretion 1 h after application in both animals. Detachment of the cornea was observed in one animal 48 h after application. The mean (24 – 48 h) cornea, conjunctivae, chemosis and iris score was 2, 2, 1.5, 1 for animal 1 and 3, 2, 2, 0 for animal 2, respectively. All effects were not reversible within 8 days. Additionally, necrosis of the eyelids, loss of hair around the eye, corrosion and purulence was observed at the end of the observation period after 8 days.

In a supporting study, one-tenth mL of sample was placed in the conjunctival sac of one eye of each of six albino rabbits (Latven, 1977). With tree of these animals, the treated eye was washed with flowing water initiated 20-30 seconds after instillation and continued for one minute; the resulting reactions were scored for seven days. In unwashed eyes, the cornea opacified rapidly. The iris was congested, ragged and failed to react to light. The conjunctivae were severely inflamed and showed scattered patches of necrosis. No signs of recovery were evident seven days after treatment. In washed eyes: the only effects of washing were to delay corneal opacification and to limit iridal effects to congestion plus a sluggish light reflex. Based on the study results, the test material is considered to be corrosive to eyes.

Justification for selection of skin irritation / corrosion endpoint:
The most reliable GLP, guideline study.

Justification for selection of eye irritation endpoint:
The best study available.

Effects on skin irritation/corrosion: irritating

Effects on eye irritation: corrosive

Justification for classification or non-classification

The available experimental test data are reliable and suitable for the purpose of classification and labelling under Regulation (EC) No.1272/2008. Based on these data, classification and labelling for skin irritation (Cat. 2) and severe eye damage (Cat. 1) is warranted.